Water-tube boiler and the like



Jan. 14, 1930. G. BURKHARDT van-an TUBE 30mm AND was mu:

2 Sheets-Sheet l Burkfiardl Firm-hey Filed Jan. 20; 1925 1 R-Li. N g J Jan. 14, 1930. s. BURKHARDT 11 WATER TUBE BQILER AND THE LIKE Filed Jan. 20, 1925 2 sheets-sheet 2 Patented Jan. 14, 1930 warren stares PATENT GFFEQE GO'ITLOB BURKHARDT, OF

HERRENALB, GERMANY, ASSIGNOR TO JULIUS M. BURY- HABDT, JOHN FRED, BURKHARDT, AND LANCE NICHOLSON, ALL OF BUFFALO, NEW

YORK

Application filed January 20, 1825, Serial No. 3,557, and. in Germany February 22, 1924.

This invention has reference to steam boilers with substantially vertically arranged water tubes, and it is intended to provide means for effecting a thorough circulation of the water and the most intimate contact of the heat with the water and the practically complete exclusion of cold streams of air from the parts of the boiler to be heated; and it is a further object of my invention to increase the accessibility of the connecting tubes and of the main bodies of the boilers, and to generally improve the construction and operation of boilers of the kinds referred to. r

In the construction of upright boilers with groups of tubes connecting an upper drum with a lower drum the arrangement is such that the lower drum is mounted in the vicinity of the furnace chamber and is liable to be exposed to unduly high temperatures with the result of dangerous heat tensions being produced in the lower drum because compensation of temperatures does not take place uniformly, even where the drum is protected against the influence of high temperatures by masonry, inasmuch as cracks and other injuries are liable to occur without being noticed. Such heat tensional strains which have frequently been the cause of the destruction of the shell of the lower drum in the case of pressures below 20 atmospheres, constitute a constant source of danger for the high-pressure boilers with the increased pressures that have been recently employed.

In view thereof means are provided by my invention for the complete elimination of the difliculties referred to, so that even in the case of the highest pressures the danger of bursting of the boiler is obviated. The arrangement according to the invention broadly speaking comprises the replacing of the lower'drum by a system of collecting tubes or headers of small diameters to which the open ends of the groups of generator tubes are connected in such a manner that the circulating current of water is adapted to pass transversely through said collecting tubes or headers. If such headers are also employed for the upper ends of the groups of generator tubes, and particularly in the case of maximum high operating pressures, the safety agalnst bursting is very considerably increased.

The invention will be more particularly described with reference to the accompanylng drawing showing by way of exemplification some of the forms of constructions in which the principles of the invention may be embodied.

In the drawings Figure 1 is an elevation with parts in crosssectional view of the new construction of boiler.

Figure 2 is a similar view with parts in section of a modified construction with two groups of ascending and descending tubes crossing each other, and with two superimposed upper drums.

Figure 3 is a cross sectional view and Figure 4 is a longitudinal section of a boiler in accordance with this invention in which the generator tubes are connected at their upper 2nd lower open ends to the headers referred Figures 5 and 6 are fragmentary axial sec-' tional views through one of the headers slightly modified.

Figure 7 is a horizontal partial section through a boiler according to Figures 3 and 4.

In Figures 8 and 9 are shown axial sections, and in Figure 10 a cross sectional view through the upper boiler section on an enlarged scale, disclosing a modification.

The substantially crescent shaped groups of ascending and descending tubes 1 and 2 (Figure 1) are in direct communication with the upper drum 16, while at their lower ends their open ends are connected to collector headers 4 of preferably circular cross section. In order to reduce the weakening of the shell of the upper drum by the boring of the communicating holes two different groups of ascending and descending tubes 1 and 2 and 1 and 2 as shown in Figure 2, may be provided. The tubes of the groups 1 and 2 in this arrangement open at their lower ends into the headers 4, and the tubes of the groups 1' and 2" open into the headers 4 which are alternately disposed between the headers 4, while at their top ends the groups lUU - of tubes 1 and 2 open up directly into the upper drum 17 and the groups of tubes 1 and 2 into the upper drum 17 arranged below the drum 17. As shown, the tubes of groups 1 and 2 extend upwardly between and in alternation with the tubes of groups 1 and 2, and by thus arranging the sets of tubes and connecting them at their upper ends to separate drums 17 and 17 instead of to a single drum, the distance between tube holes in the drums is increased, so that undue weakening of either drum is avoided. Such drums as disclosed in Figure 2 on account of the reduced weakening of the shell of the upper drum by the arrangement of the bore holes are more suitable for higher pressure than the construction according to Figure 1.

As'shown, the top and bottom collectors formed by the drums and headers are arranged in alinement coaxially of the boiler, the axisof which is inclined to the vertical so as to dispose the ascending group or groups of tubes immediately above the fire-box A at one side of the base of the boiler shell or casing and the descendingtubes above a discharge flue B torthe wastegases at the opposite side of the base of the boiler shell or casing. A hollow refractory partition or bridge wall 13, from which the bafi le plates 1%15 rise, forms a base support for the groups of tubes and, with the plates 1415, closes direct communication between the fireboxand discharge flue. The ascending tubes are, therefore, exposed to the direct heat of the flames from the fire-box and the combu tion gases are caused to fiowfirst upwardly between the ascending tubes, then across over the tops of the battles 1%15 and down between the descending tubes to the flue B. By this means the Water flowing through the ascending tubes is heated to a higher degree than the water flowing through the descending tubes, so that the rapid upfl'ow of the more highly heated water in the ascending tubes induces a 'downfiow of the less highly heated water in the descending tubes. The water flowing from the upper drum or drums down through the descendingtubes to the lower headers is thus gradually heated and passes into the ascending tubes for upflow therein and rapid conversion into steam. This construction ensures economy and ethciency in the use of the heat and the avoidance of the heating of large masses of water at a time, as well as a reduction in size of the boiler, without sacrifice of steam generating capacity as compared with large sizes of boilers of the water tube type in which all the tubes of the boiler are subjected en masse more or less directly to heat of the flames and gases from the fire-box.

In order to arrive at a particularly safe and reliable arrangement for the highest pressures the ascending and descending groups of tubes 1 and 2, as shown in Figures 3 and 4 of the drawing, may be caused to terminate at their lower and upper ends in headers 4 and 3, the upper drum 8 being connected to the upper headers alternately by the tubes 5, 6 and 7 through which the bubbles of steam evolved from the circulating current in the upper headers rise into the upper drum 8, and also by the small tubes 9 by means of which so much water in the unit of time is admitted from the upper drum into the headers 3, as steam'fiows into the upper drum. The. points of communication of the sets of tubes with the headers 3 are oppositely arranged, as shown in Figure 6, so that the circulating streams are adapted to flow from the points of entry of the descending tubes to those of the ascending tubes through the collector and transversely relative to the axis thereof. 7 c The headers, as shown in Figures 6, 9 and 10, are provided with short tubes or nipples 18 by means of which the boiler tubes may be connected. In order to prevent disturbance of the transversely flowing water currents by the rising bubbles of. steam inthe upper headers I provide semi-circularly curved sheet metal'troughs or channels 19 with elliptically compressed or narrowed middle portion extending across the headers between opposed nipples; In the case of descending tubes of smaller diameter than theascencling. tubes these guide troughs are cone shaped.

By means of the connection of the upper headers 3 and the upper drum 8 by means of the alternately arranged steam tubes 5, 6 and 7 the weakening of the shell of the upper drum by the boring of the holes is reduced to a minimum. The upper drum is disposed entirely at the outside of the masonry of the boiler, and it is completely protected against the action of the furnace gases. g The lower headers are disposed in accordance with the arrangement shown with reference to F i-gures 1 and 2, and as in Figures 1 and 2 they are connected by small tubes 10 to a mud collector or trap 11.

The tubes a and b of the groups of ascending and descending tubes are alternately turned to the left and to the right respectively, as shown in Figures 4 and 7, by which means they are caused to twice cross each other in their entire length. By this means a very efiicient whirling and mixing motion of the heating gases flowing along the tubes is produced, which is of great importance for the transmission of heat. The vacant channels, ordinarily formed between the series of tubes in the case of rather great distance of the headers from one another, are filled up by the eflicient heating surface. Moreover,

with this arrangement, as appears from F igures 7 and 10, the ends of the ascending and descending tubes are situated on an axis intersecting the axis of said headers, and the planes of the individual bow-shaped tubes intersect on a straight line coinciding with the axis of the headers.

In order to also completely protect the headers 3 and 4c with their connecting tubes and tube connections against the influence of the furnace gases, and in order to also provide for their being accessible from the outside even during operation, the substantially trough-shaped tube enclosing, Wall plates or shields 12 and 13 are so arranged that they are protected on their outside by fireproof masonry against the action of the heating gases. The lower headers are always accessible from a ground or floor level, and the upper headers and drum or drums may always be reached from the top of the boiler.

In addition tothe plates or the like 14, 15 of substantially bow-shaped configuration at the insides of the tube groups, any other supporting staying and protecting means may be resorted to. It should also be understood that the shape and configuration of the headers may deviate from the shape herein shown merely by way of exemplification and other changes and modifications of the shape, and arrangements of parts may be made within the scope of the invention to meet the various requirements of use without deviating from the spirit and scope of the invention, as defined by the claims hereunto appended.

I claim:

1. In an upright boiler, in combination, a plurality of upper and a plurality of lower headers, groups of substantially bow-shaped axially inclined, and substantially adjacently disposed and similarly arranged pipes, terminating in transverse alinement in the upper and lower headers on opposite sides thereof, trough-shaped connecting channels within and extending across the headers between the transversely alined terminals of the pipes, and heating means for the pipes.

2. An upright water tube boiler having its axis inclined at an angle to the vertical and comprising opposed groups of substantially crescent-shaped tubes arranged on opposite sides of the boiler axis, a water and steam collector communicating withthe upper ends of the groups of tubes, a header connecting the tially crescent-shaped tubes arranged on opposite sides of the boiler axis, headers connecting the tubes at their upper and lower ends, like ends of the tubes of the groups opening into the opposite sides of each header in transverse alinement with each other, trough-shaped conductors extending transversely within the headers between alined ends of the opposed tubes of the groups, and means for heating the tubes at one side of the boiler to a higher temperature than the tubes at the opposite side of the boiler so as to cause a fluid upflow through the tubes at one side and a fluid downfiow through the tubes at the other side.

In testimony whereof I aiiix my signature.

GOTTLOB BURKHARDT.

lower ends of the groups of tubes, the collector and header being arranged in the plane of the boiler axis and the lower ends of the tubes of the groups opening into opposite sides of the header in transverse alinement with each other, open-topped troughs arranged within the header between the transversely alined lower ends of the groups of tubes opening thereinto, and means for heating the groups of tubes to different degrees so as to cause a fluid upflow through one group of tubes and a fluid downflow through the other group of tubes.

3. An upright water tube boiler having its axis inclined at an angle tothe vertical and comprising opposed groups of substan- 

